A core update is a significant, broad change to Google’s search algorithms and systems. Google runs several a year, with the aim of showing helpful and reliable results. A core update does not target specific websites or pages. Google announces each core update in its list of ranking updates, with a start and an end date.
Why does it matter?
After a core update, rankings can shift even if you have changed nothing on your website. That does not automatically mean your site has a problem. Google says most sites do not need to do anything.
How do you check it?
- Check whether the update has finished rolling out; Google lists the end date.
- Then wait at least a week and compare a period before and after the update in Google Search Console.
- According to Google, a small drop does not call for drastic action. With a large, lasting drop, it is time to take a broader look at whether your content is helpful, reliable and written for people.
Common mistake
Rushing to change or remove pages in the hope of reversing the loss. Google advises against quick fixes and calls removing content a last resort. Improvements can take anywhere from a few days to several months before Google’s systems pick them up.
Why SEO takes time is explained in How long does SEO take to show results?